NYCTEA N1VEA. 
267 
GENUS I. NYCTEA. THE WHITE OWLS. 
Gen. ('ii. The sternum is considerably arched, with a moderately rounded keel which does not equal in heiyht one half 
the width of the sternum. Outer marginal indentations, more than twice the depth of the inner. Coracoids, short, not be¬ 
ing equal in length to the top of the keel and are set on at a rather wide angle. Furcula, quite well developed. Tail and wings, 
long. 
Members of this genus are particularly noticeable on account of the prominent white markings to the plumage which 
is strikingly long and downy. The eyes are large and yellow in color. The sterno-trachealis is quite stout, and there is 
a slender bronchialis, but no other laryngeal muscles. The oesophagus is nearly straight, being a little wider in the mid¬ 
dle, and opens into a small proventriculus with simple, oval glands arranged in a narrow, zonular band which measures 
about TOO in width. Thestomach is small, flat m form, with somewhat irregular outlines, and with very thin walls. The 
coeca are quite long, small near the intestine, measuring GO in diameter, with.the blind ends dilated into long, oval sacs, 
•25 in diameter by 1'50 in length. The fold of the duodenum is long, inclosing a small, narrow pancreas. The spleen is an 
elliptical body lying directly on the proventriculus. Both lobes of the liver are nearly equal in size. There is but one spe¬ 
cies within our limits. 
NYCTEA NIVEA. 
Snowy Owl. 
Nyctea nivea Steph., Cont. of Shaw’s Zool., XIII; 1826, 62. 
DESCRIPTION. 
Sp. Ch. Form, robust. Size, very large. Sternum, stout. Tongue, rather thick and fleshy, horny at the tip which 
is rounded but not bifid. The bill and claws are very strong and well curved, long, but are nearly concealed by long, brist¬ 
ly feathers. 
Color. Adult male. Pure snowy-white, more or less mottled, spotted, and barred, especially above, with a very dark- 
brown, but the white predominates. 
Adult female. White, as in the male, but with the dark markings much more prominent, frequently extending over 
both surfaces including wings and tail. The face, chin, throat, under wing-coverts, tibia, and tarsus are always perfectly 
immaculate. 
Young. Similar to the adult but much more widely barred with dark-brown, and also show a tinging of yellowish- 
rufous on the back. Iris, yellow, cere, greenish, bill and claws, greenish-brown, in all stages. 
OBSERVATIONS. 
There is considerable variation in amount of dark-brown markings but this is evidently the result of age and sex, other¬ 
wise specimens are quite uniform in color. Very old birds become nearly, or wholly white. Distributed, as a constant res¬ 
ident, throughout the more northern portions of both Continents, migrating southward in winter, in North America, reg¬ 
ularly, at least, to New Jersey and rarely as far as South Carolina. 
DIMENSIONS. 
Average measurements of male specimens. Length, 22'50; stretch, 59-00; wing, 16 - 75; tail, 8'55; bill, 1*30; tarsus, 
1*95. Longest specimen, 23 - 00; greatest extent of wing, 60 - 00; longest wing, 17 - 35; tail, 8'85; bill, 1*35; tarsus,2-00. 
Shortest specimen, 22'00; smallest extent of wing, 58 - 00; shortest wing, 16-00; tail, 8‘27; bill, 125; tarsus, l - 90. 
Average measurements of female specimens. Length, 23'70; stretch, 60’54; wing, 17’25; tail, 9 - 35; bill, 1*45; tarsus, 
2 - 25. Longest specimen, 25'00; greatest extent of wing, 62'25; longest wing, 17'50; tail, 9'85; bill, 1'50; tarsus, 2-50. 
Shortest specimen, 22-50; smallest extent of wing, 58-83; shortest wing, 16-90; tail, 8'85; .bill, 1’40; tarsus, 2 00. 
DESCRIPTION OF NESTS AND EGGS. 
Nests, placed on the ground, composed of sticks, twigs, grass, etc., lined with grass and weeds. They are bulky 
structures. 
Eggs, three or four in number, oblong-oval in form, white in color, with the surface very smooth. Dimensions from 
1-85x2-50 to 1-90 x 2-55. 
HABITS. 
Fortunate for admirers of the Snowy Owls, these beautiful birds are migratory, for if 
they did not choose to come to us we should seldom be gratified by a sight of their mag- 
